At 90 million, India ranked second in the number of adults living with diabetes in 2024. China was first at 148 million and the US ranked third at 39 million, according to a study published in The Lancet Diabetes and Endocrinology journal.
Researchers, including those from the International Diabetes Federation in Belgium and the India Diabetes Research Foundation and Dr A Ramachandran's Diabetes Hospital in Chennai, said countries with large populations, such as China, India, the US, and Pakistan, contribute a very large share of the number of people with diabetes worldwide.
They projected that Pakistan could surpass the US by 2050.
The eleventh edition of the International Diabetes Federation (IDF) Diabetes Atlas provides national, regional and global diabetes prevalence estimates for 2024, with projections to 2050.
Estimates were provided for 215 countries and territories after analysing 246 studies conducted between 2005 and 2024.
Over 11 per cent of the world's adult population, or 589 million adults aged 20-79, were affected by the metabolic disorder in 2024 and nearly 13 per cent (853 million adults) are projected to be affected by 2050, the study said.
"In 2024, one in nine adults worldwide was living with diabetes. The number of adults with diabetes in 2024 exceeded 500 million and is projected to rise to close to 900 million by 2050," the authors wrote.
"In 2024, the largest number of adults with diabetes aged 20-79 years was in China (148 million), followed by India (90 million), and the US (39 million)," they said.
Over four-fifths of the world's diabetes population, or 80.64 per cent, were estimated to be living in low and middle-income countries in 2024. The countries could also be expected to see more than 95 per cent of the global increase in cases by 2050.
The increase reflects population growth, population ageing, and ongoing urbanisation, all of which contribute to the rising number of cases of the chronic condition, the researchers said.
Monitoring diabetes burden around the world requires support for data collection in resource-poor settings, which are expected to experience substantial increases in diabetes prevalence, they said.
Prevalence was found to peak at nearly 25 per cent among the world's adults aged 75-79. Diabetes prevalence was also higher among men than women, and in urban than rural areas, the study found.
Middle-income countries had the highest prevalence (11.46 per cent of adults aged 20-79), followed by high-income (10.21 per cent) and low-income countries (7.47 per cent).
The team added that the diabetes epidemic has continued unchecked since the turn of the millennium, and stronger efforts are needed to slow its progression, with strategies tailored appropriately across countries and population groups.